Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/mfd/ti_am335x_tscadc.c

  1 /*
  2  * TI Touch Screen / ADC MFD driver
  3  *
  4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License as
  8  * published by the Free Software Foundation version 2.
  9  *
 10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 11  * kind, whether express or implied; without even the implied warranty
 12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  */
 15 
 16 #include <linux/module.h>
 17 #include <linux/slab.h>
 18 #include <linux/err.h>
 19 #include <linux/io.h>
 20 #include <linux/clk.h>
 21 #include <linux/regmap.h>
 22 #include <linux/mfd/core.h>
 23 #include <linux/pm_runtime.h>
 24 #include <linux/of.h>
 25 #include <linux/of_device.h>
 26 #include <linux/sched.h>
 27 
 28 #include <linux/mfd/ti_am335x_tscadc.h>
 29 
 30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
 31 {
 32         unsigned int val;
 33 
 34         regmap_read(tsadc->regmap_tscadc, reg, &val);
 35         return val;
 36 }
 37 
 38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
 39                                         unsigned int val)
 40 {
 41         regmap_write(tsadc->regmap_tscadc, reg, val);
 42 }
 43 
 44 static const struct regmap_config tscadc_regmap_config = {
 45         .name = "ti_tscadc",
 46         .reg_bits = 32,
 47         .reg_stride = 4,
 48         .val_bits = 32,
 49 };
 50 
 51 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val)
 52 {
 53         unsigned long flags;
 54 
 55         spin_lock_irqsave(&tsadc->reg_lock, flags);
 56         tsadc->reg_se_cache = val;
 57         if (tsadc->adc_waiting)
 58                 wake_up(&tsadc->reg_se_wait);
 59         else if (!tsadc->adc_in_use)
 60                 tscadc_writel(tsadc, REG_SE, val);
 61 
 62         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
 63 }
 64 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
 65 
 66 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 67 {
 68         DEFINE_WAIT(wait);
 69         u32 reg;
 70 
 71         /*
 72          * disable TSC steps so it does not run while the ADC is using it. If
 73          * write 0 while it is running (it just started or was already running)
 74          * then it completes all steps that were enabled and stops then.
 75          */
 76         tscadc_writel(tsadc, REG_SE, 0);
 77         reg = tscadc_readl(tsadc, REG_ADCFSM);
 78         if (reg & SEQ_STATUS) {
 79                 tsadc->adc_waiting = true;
 80                 prepare_to_wait(&tsadc->reg_se_wait, &wait,
 81                                 TASK_UNINTERRUPTIBLE);
 82                 spin_unlock_irq(&tsadc->reg_lock);
 83 
 84                 schedule();
 85 
 86                 spin_lock_irq(&tsadc->reg_lock);
 87                 finish_wait(&tsadc->reg_se_wait, &wait);
 88 
 89                 reg = tscadc_readl(tsadc, REG_ADCFSM);
 90                 WARN_ON(reg & SEQ_STATUS);
 91                 tsadc->adc_waiting = false;
 92         }
 93         tsadc->adc_in_use = true;
 94 }
 95 
 96 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
 97 {
 98         spin_lock_irq(&tsadc->reg_lock);
 99         am335x_tscadc_need_adc(tsadc);
100 
101         tscadc_writel(tsadc, REG_SE, val);
102         spin_unlock_irq(&tsadc->reg_lock);
103 }
104 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
105 
106 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc)
107 {
108         unsigned long flags;
109 
110         spin_lock_irqsave(&tsadc->reg_lock, flags);
111         tsadc->adc_in_use = false;
112         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
113         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
114 }
115 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
116 
117 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
118 {
119         unsigned long flags;
120 
121         spin_lock_irqsave(&tsadc->reg_lock, flags);
122         tsadc->reg_se_cache &= ~val;
123         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
124         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
125 }
126 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
127 
128 static void tscadc_idle_config(struct ti_tscadc_dev *config)
129 {
130         unsigned int idleconfig;
131 
132         idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
133                         STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
134 
135         tscadc_writel(config, REG_IDLECONFIG, idleconfig);
136 }
137 
138 static  int ti_tscadc_probe(struct platform_device *pdev)
139 {
140         struct ti_tscadc_dev    *tscadc;
141         struct resource         *res;
142         struct clk              *clk;
143         struct device_node      *node = pdev->dev.of_node;
144         struct mfd_cell         *cell;
145         struct property         *prop;
146         const __be32            *cur;
147         u32                     val;
148         int                     err, ctrl;
149         int                     clock_rate;
150         int                     tsc_wires = 0, adc_channels = 0, total_channels;
151         int                     readouts = 0;
152 
153         if (!pdev->dev.of_node) {
154                 dev_err(&pdev->dev, "Could not find valid DT data.\n");
155                 return -EINVAL;
156         }
157 
158         node = of_get_child_by_name(pdev->dev.of_node, "tsc");
159         of_property_read_u32(node, "ti,wires", &tsc_wires);
160         of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
161 
162         node = of_get_child_by_name(pdev->dev.of_node, "adc");
163         of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
164                 adc_channels++;
165                 if (val > 7) {
166                         dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
167                                         val);
168                         return -EINVAL;
169                 }
170         }
171         total_channels = tsc_wires + adc_channels;
172         if (total_channels > 8) {
173                 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
174                 return -EINVAL;
175         }
176         if (total_channels == 0) {
177                 dev_err(&pdev->dev, "Need atleast one channel.\n");
178                 return -EINVAL;
179         }
180 
181         if (readouts * 2 + 2 + adc_channels > 16) {
182                 dev_err(&pdev->dev, "Too many step configurations requested\n");
183                 return -EINVAL;
184         }
185 
186         /* Allocate memory for device */
187         tscadc = devm_kzalloc(&pdev->dev,
188                         sizeof(struct ti_tscadc_dev), GFP_KERNEL);
189         if (!tscadc) {
190                 dev_err(&pdev->dev, "failed to allocate memory.\n");
191                 return -ENOMEM;
192         }
193         tscadc->dev = &pdev->dev;
194 
195         err = platform_get_irq(pdev, 0);
196         if (err < 0) {
197                 dev_err(&pdev->dev, "no irq ID is specified.\n");
198                 goto ret;
199         } else
200                 tscadc->irq = err;
201 
202         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
203         tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
204         if (IS_ERR(tscadc->tscadc_base))
205                 return PTR_ERR(tscadc->tscadc_base);
206 
207         tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
208                         tscadc->tscadc_base, &tscadc_regmap_config);
209         if (IS_ERR(tscadc->regmap_tscadc)) {
210                 dev_err(&pdev->dev, "regmap init failed\n");
211                 err = PTR_ERR(tscadc->regmap_tscadc);
212                 goto ret;
213         }
214 
215         spin_lock_init(&tscadc->reg_lock);
216         init_waitqueue_head(&tscadc->reg_se_wait);
217 
218         pm_runtime_enable(&pdev->dev);
219         pm_runtime_get_sync(&pdev->dev);
220 
221         /*
222          * The TSC_ADC_Subsystem has 2 clock domains
223          * OCP_CLK and ADC_CLK.
224          * The ADC clock is expected to run at target of 3MHz,
225          * and expected to capture 12-bit data at a rate of 200 KSPS.
226          * The TSC_ADC_SS controller design assumes the OCP clock is
227          * at least 6x faster than the ADC clock.
228          */
229         clk = clk_get(&pdev->dev, "adc_tsc_fck");
230         if (IS_ERR(clk)) {
231                 dev_err(&pdev->dev, "failed to get TSC fck\n");
232                 err = PTR_ERR(clk);
233                 goto err_disable_clk;
234         }
235         clock_rate = clk_get_rate(clk);
236         clk_put(clk);
237         tscadc->clk_div = clock_rate / ADC_CLK;
238 
239         /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
240         tscadc->clk_div--;
241         tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
242 
243         /* Set the control register bits */
244         ctrl = CNTRLREG_STEPCONFIGWRT |
245                         CNTRLREG_STEPID;
246         if (tsc_wires > 0)
247                 ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
248         tscadc_writel(tscadc, REG_CTRL, ctrl);
249 
250         /* Set register bits for Idle Config Mode */
251         if (tsc_wires > 0)
252                 tscadc_idle_config(tscadc);
253 
254         /* Enable the TSC module enable bit */
255         ctrl = tscadc_readl(tscadc, REG_CTRL);
256         ctrl |= CNTRLREG_TSCSSENB;
257         tscadc_writel(tscadc, REG_CTRL, ctrl);
258 
259         tscadc->used_cells = 0;
260         tscadc->tsc_cell = -1;
261         tscadc->adc_cell = -1;
262 
263         /* TSC Cell */
264         if (tsc_wires > 0) {
265                 tscadc->tsc_cell = tscadc->used_cells;
266                 cell = &tscadc->cells[tscadc->used_cells++];
267                 cell->name = "TI-am335x-tsc";
268                 cell->of_compatible = "ti,am3359-tsc";
269                 cell->platform_data = &tscadc;
270                 cell->pdata_size = sizeof(tscadc);
271         }
272 
273         /* ADC Cell */
274         if (adc_channels > 0) {
275                 tscadc->adc_cell = tscadc->used_cells;
276                 cell = &tscadc->cells[tscadc->used_cells++];
277                 cell->name = "TI-am335x-adc";
278                 cell->of_compatible = "ti,am3359-adc";
279                 cell->platform_data = &tscadc;
280                 cell->pdata_size = sizeof(tscadc);
281         }
282 
283         err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
284                         tscadc->used_cells, NULL, 0, NULL);
285         if (err < 0)
286                 goto err_disable_clk;
287 
288         device_init_wakeup(&pdev->dev, true);
289         platform_set_drvdata(pdev, tscadc);
290         return 0;
291 
292 err_disable_clk:
293         pm_runtime_put_sync(&pdev->dev);
294         pm_runtime_disable(&pdev->dev);
295 ret:
296         return err;
297 }
298 
299 static int ti_tscadc_remove(struct platform_device *pdev)
300 {
301         struct ti_tscadc_dev    *tscadc = platform_get_drvdata(pdev);
302 
303         tscadc_writel(tscadc, REG_SE, 0x00);
304 
305         pm_runtime_put_sync(&pdev->dev);
306         pm_runtime_disable(&pdev->dev);
307 
308         mfd_remove_devices(tscadc->dev);
309 
310         return 0;
311 }
312 
313 #ifdef CONFIG_PM
314 static int tscadc_suspend(struct device *dev)
315 {
316         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
317 
318         tscadc_writel(tscadc_dev, REG_SE, 0x00);
319         pm_runtime_put_sync(dev);
320 
321         return 0;
322 }
323 
324 static int tscadc_resume(struct device *dev)
325 {
326         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
327         unsigned int restore, ctrl;
328 
329         pm_runtime_get_sync(dev);
330 
331         /* context restore */
332         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
333         if (tscadc_dev->tsc_cell != -1)
334                 ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
335         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
336 
337         if (tscadc_dev->tsc_cell != -1)
338                 tscadc_idle_config(tscadc_dev);
339         restore = tscadc_readl(tscadc_dev, REG_CTRL);
340         tscadc_writel(tscadc_dev, REG_CTRL,
341                         (restore | CNTRLREG_TSCSSENB));
342 
343         tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
344 
345         return 0;
346 }
347 
348 static const struct dev_pm_ops tscadc_pm_ops = {
349         .suspend = tscadc_suspend,
350         .resume = tscadc_resume,
351 };
352 #define TSCADC_PM_OPS (&tscadc_pm_ops)
353 #else
354 #define TSCADC_PM_OPS NULL
355 #endif
356 
357 static const struct of_device_id ti_tscadc_dt_ids[] = {
358         { .compatible = "ti,am3359-tscadc", },
359         { }
360 };
361 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
362 
363 static struct platform_driver ti_tscadc_driver = {
364         .driver = {
365                 .name   = "ti_am3359-tscadc",
366                 .owner  = THIS_MODULE,
367                 .pm     = TSCADC_PM_OPS,
368                 .of_match_table = ti_tscadc_dt_ids,
369         },
370         .probe  = ti_tscadc_probe,
371         .remove = ti_tscadc_remove,
372 
373 };
374 
375 module_platform_driver(ti_tscadc_driver);
376 
377 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
378 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
379 MODULE_LICENSE("GPL");
380 

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